THE EARLY DAYS OF CHEMISTRY 17 



should seem that an accurate distinction has not been 

 made between the different states in which it exists ; that 

 is, between the phenomena of fire actually existing as a 

 principle in the composition of bodies, and those which 

 it exhibits when existing separately, and in its natural 

 state : nor have proper distinct appellations been assigned 

 to it in these different circumstances. In the latter state, 

 we may properly give it the names of fire, matter of the 

 sun, of light, and of heat ; and may consider it as a sub- 

 stance composed of infinitely small particles, continually 

 agitated by a most rapid motion, and of consequence essen- 

 tially fluid.' ' The greatest change produced on bodies, 

 by its presence or its absence, is the rendering them 

 fluid or solid; so that all other bodies may be deemed 

 essentially solid; fire alone essentially fluid, and the 

 principle of fluidity in others. This being presupposed, 

 air itself might become solid, if it could be entirely de- 

 prived of the fire it contains ; as bodies of most difficult 

 fusion become fluid, when penetrated by a sufficient 

 quantity of the particles of fire.' 



An attempt has been made in the preceding pages to 

 show the manner in which the world around us was 

 regarded. People were content to take as true what they 

 were told ; in fact, it was regarded as unfitting that the 

 ' mysteries ' with which we are surrounded should be too 

 minutely inquired into. Great reverence was paid to 

 tradition; and more attention to the celebrity and per- 

 sonal character of those who advocated certain dogmas 

 than to the evidence in favour of their intrinsic probability. 



This spirit is by no means extinct; the vast majority 

 of the human race are content to gain knowledge at 

 second hand. Whether such knowledge is worth having 

 may well be questioned; it is of course impossible that 

 every man should investigate natural phenomena for 

 himself ; but it is at least possible to place every child in 



B 



